The present invention relates to a fuel injection timing control system for a diesel engine.
The optimization of diesel engine performance requires very accurate control of fuel injection timing. It would be even more desirable to control the timing of the start of combustion (SOC), but SOC can only be controlled indirectly by controlling fuel injection timing. Variations in fuel quality and engine operating conditions influence the ignition delay time between fuel injection turn-on and actual start of combustion. Thus, the ability of open loop fuel injection control systems to accurately control SOC is limited. Closed loop control systems for the control of spark timing in ignition-type (gasoline) engines have been proposed to achieve minimum spark advance for best torque or maximum power under various operating conditions. However, such systems are not suitable for use with a fuel-injected diesel engine.